Editing shape after parenting armatures
Your weight paints are probably off. Click on your model, switch to weight paint mode, go to Object data properties panel, and click on the bone causing the problem under vertex groups. Where the problem is occurring, there should be red dots. Change the brush type to subtract and make the color of the red spots causing the problem blue.
Here is where you click on your bone:

Click on the option that has the name of the bone causing the problem.
If you want me to elaborate, just ask.